Spec U Headers Installed...need more power

[x-runner kid]

So for those that have watched this looking for the buzz updates here is mine. I relocated my front o2 sensors to the collectors at the header and no change in my buzz. I then checked my V-band connection at the y pipe collector and I had a pretty good size exhaust leak so I sealed it up as well as wrapped my Y collector with header wrap (G said it would help the sound) and it's still there. The buzz is exactly the same as it was before. There are only two things I can think to do now. Option 1: switch the magnaflow muffler out for a different muffler. Option2: weld in two vibrant high flow resonators into the Y pipe.

 

[fishsticks]

I'm subbing to this thread just to see how you guys come along. I started a thread in the FI section thinking I may have had a boost leak. I went through all the motions you guys have with checking for leaks on the exhaust side and intake side.

Initially I didn't think the sound you guys were posting was the same as mine. After spending a couple weeks losing sleep and then rewatching some of the early videos in this thread, I'm not so sure.

I've just gotten used to it. Mine is like Old Faithful and comes on at 2200 RPM under moderate throttle then goes away above 4000. I was actually contemplating if I had a leak in the ACIS valve, since it closes at 2100RPM with 60* of throttle blade angle.

I ran the exhaust with stock manifolds for a couple days and it had no weird sound. I'm thinking the change in exhaust gas velocity once I installed the headers brought mine on. This would line up with the results from guy who put his JBA shorties back on and had his sound go away.

I'll admit, I have no prior experience with tuned length Y pipes. In past vehicles I've just gone directly to an X or H pipe system and dual exits. This is my DD though, so I'm trying to keep the custom fab on it to a minimum and URD makes some nice hardware. The pulse merge that G has mentioned makes sense.

Here's my video for reference.

https://www.youtube.com/watch?v=Rv8o0G0Y1CQ

 

[x-runner kid]

You have the full spec-u system correct? Mine makes the buzz at anything more than a quarter throttle. Usually around 2200-3k.

 

[fishsticks]

You have the full spec-u system correct? Mine makes the buzz at anything more than a quarter throttle. Usually around 2200-3k.

I do, from the headers back. Mine comes on at similar RPM/TPS% to yours. To me it sounds more like an air rushing/turbulence sound, but I could see how it might be considered a buzz.

 

[x-runner kid]

It sounds similar to me as well. And sometimes I can hear it once I let off the throttle in the higher rpms on deceleration. I'm going to drive it a bit more and see if I did in fact fix the leak at the V-band. Everyone loves the v-band flanges that I talk to but I honestly prefer a crush gasket and 2 or 3 bolt flange like what's on the headers.

 

[fishsticks]

It sounds similar to me as well. And sometimes I can hear it once I let off the throttle in the higher rpms on deceleration. I'm going to drive it a bit more and see if I did in fact fix the leak at the V-band. Everyone loves the v-band flanges that I talk to but I honestly prefer a crush gasket and 2 or 3 bolt flange like what's on the headers.

The sound you're hearing on deceleration is typical of freer flowing exhaust systems. There are some physics behind it, but I'm a few drinks in and probably not equipped to explain it properly right now. :rolleyez:

I would have rather had a slip fit at that joint, but I see the appeal of a v band there. I've considered having it TIG welded there and not dealing with the clamp, but I believe I have mine sealed up now.

 

[x-runner kid]

The sound you're hearing on deceleration is typical of freer flowing exhaust systems. There are some physics behind it, but I'm a few drinks in and probably not equipped to explain it properly right now. :rolleyez:

I would have rather had a slip fit at that joint, but I see the appeal of a v band there. I've considered having it TIG welded there and not dealing with the clamp, but I believe I have mine sealed up now.

I have thought about welding it up as well or even cutting out the v-band and replacing it with a different 3 bolt flange and gasket. I think I understand what you are saying about the free flowing sound though.

 

[JPAYNE722]

Found out mine was rubbing on the sway bar link and causing a buzzing sound lol

 

[jimx]

I bought a gm v-band kit today from work. the kit comes with a round gasket. This kit is part of a duramax recall. Ill let you guys know this weekend how it go.

 

[x-runner kid]

Found out mine was rubbing on the sway bar link and causing a buzzing sound lol

Really? That whole time that's what yours ended up being? What part was rubbing there?

I bought a gm v-band kit today from work. the kit comes with a round gasket. This kit is part of a duramax recall. Ill let you guys know this weekend how it go.

I was thinking about this yesterday. I was wondering why there is no gasket at the V-band, but I have never used a v-band so I figured that was normal. Def keep us updated. I bought two universal clamp on hangers for the Y pipe to be able to mount to the oem hanger locations with the rubber bushings.

 

[JPAYNE722]

Oh no it still "buzzes?" But not as bad lol right by the sway bar link,i used a clamped and just pulled it away

 

[x-runner kid]

Oh no it still "buzzes?" But not as bad lol right by the sway bar link,i used a clamped and just pulled it away

Oh damn I was hoping it would of fixed it haha.

 

[JPAYNE722]

U swap mufflers yet?

 

[4x4fiend]

I've got similar sound under hard acceleration, it goes away once the system is warmed up though. I'm only running the headers to stock y-pipe and exhaust, so likely a matching y-pipe would help.

I think of it as a reminder to not go hard on the engine till things are warmed up.

 

[x-runner kid]

U swap mufflers yet?

Not yet I haven't. I have been talking with another member through pm and he's going to be trying it. I got some clamp on hangers to mount on the Y pipe that will use the oem rubber bushings and mount in the stock locations that I'm going to try first. Then possibly a resonator if the other members muffler swap doesn't do it.

I've got similar sound under hard acceleration, it goes away once the system is warmed up though. I'm only running the headers to stock y-pipe and exhaust, so likely a matching y-pipe would help.

I think of it as a reminder to not go hard on the engine till things are warmed up.

I have noticed it can be worse when the truck is cold but it's still very real and loud when my truck is warmed up.

 

[4x4fiend]

Anyone have any sound clips of N/A with spec-u headers and y-pipe - stock y-pipe back?

kid - if you've got a goPro and keen on there being something wrong, maybe best to strap the goPro under the truck to the trans crossmember rather than in the cab. To me it sounds like the same sound I've got and it's likely pulse from the headers entering the stock y-pipe. The reason it sounds like passenger side is your probably hearing it out the exhaust tip on the passenger side.

 

[x-runner kid]

I have the full spec-U system headers and all. So no stock Y pipe. I do have a go pro and I may just have to strap it on the truck so everyone can hear a quality clip of the buzz/rattle I am talking about.

 

[4x4fiend]

ahh, thought you just had the headers sorry

 

[x-runner kid]

No worries. Gonna do some more searching today and see if I can figure it out.

 

[jimx]

Really? That whole time that's what yours ended up being? What part was rubbing there?

I was thinking about this yesterday. I was wondering why there is no gasket at the V-band, but I have never used a v-band so I figured that was normal. Def keep us updated. I bought two universal clamp on hangers for the Y pipe to be able to mount to the oem hanger locations with the rubber bushings.

I made no difference after the installation. I think your idea of putting hangers and rubber bushings might tone the vibration sound down.